Monday, February 1, 2010

All you ever want to know about PCs: Graphic Cards

There has not been much excitement until recently with graphic cards as they finally manage to play even the most demanding games on the highest details with decent frame rates. Just right now I throw a bunch of gamer jargon at you. Frame rates are the number frames per seconds. Just like picture frames in a movie, a game draws the most 60 frames per second on the screen. A movie only uses 24 frames per second which is the bare minimum before the film looks choppy. Games on the other hand are not like films, since the images present differently than what is captured on film the minimum comfortable frames per second for us is 30. Anything above 80 frames per second will actually have not meaning and will affect gameplay. A little more on that later.

The real actual bottleneck to your gaming pleasure is not your graphic card, RAM or CPU. No, it is really your monitor. You monitor’s maximum resolution and refresh rate (Hz) should determine the graphic card you are going to get. In that sense benchmarks by reviewers give a good indication. If your monitor resolution is 1680 x 1050 and the card you are looking plays your favourite game at 120fps on the same system specs do not expect to see 120fps on your screen. If you monitor has only 60hz then out of that 120fps it will only 60fps as 1hz is considered 1fps. This can cause screen tearing when you move a lot in the game along with some dropped frames that looks like lag. So choose carefully on just how much juice you want to squeeze out of the card and just how much you can really drink.

Another thing to remember is that the newest generation of graphics cards although more power efficient than the last will still use about 100watts of power at least when gaming. So calculate your total system requirement to see if you need to purchase a new PSU just to support your new card. You can use this PSU calculator from Thermaltake http://www.thermaltake.outervision.com/ to get a general idea of what you may need.

Next you need to make sure your motherboard supports the format of the graphic card you are interested in. There are 3 main formats for graphics in use; PCI, AGP and PCI-E. As you may know PCI is the oldest and is still in use for mainly CCTV recording and other video recording activities. AGP is the old standard that has been replaced by PCI-E. PCI slots are generally white in colour while AGP slots are brown with PCI-E being less colour restricted.

Graphic cards have a huge variety of output ports that they can work on. It is surprising but there are 6 main ports for graphic cards. DVI and VGA are the current main ouputs for PCs while DisplayPort and HDMI are the newer replacements for S-Video and Composite Video for TVs. Out of these 6, DisplayPort and HDMI are the only ones that carry both audio and video out of the card with DisplayPort slowly replacing HDMI.

Like all PC devices graphic cards tend to fail in 3 years. The main cause of failure is usually heat. Fans slow down as oil evaporate or leak from momentum and heat. Heatsinks get coated in dust and oil from no maintenance and thermal paste turns into thermal dust doing its job.

Heat also affects components near the source which is usually the GPU of the graphic card. While GPU can cook at 80C to 90C happily, capacities and mosfets distaste the high heat and go boom. This causes your graphic card to become unstable and shortly stop booting.

Other than heat power surges are another cause for alarm. If your graphic card is powered directly from the PSU and not from the motherboard any power surge that kills the PSU will likely take out the graphic card with the motherboard.

Although we cannot do much against power surges except getting better regulators to put in-between the PC and the wall socket we can get 3rd party coolers that provide better heat dissipation then the stock cooler that comes with the card.

The final way to kill a graphic card is a by-product of our greed/curiosity; overclocking. Just like CPUs pushing higher voltages and not cooling the card adequately either cause the card to overheat and cook GPU or/and RAM or it will quicken electromigration which shortens the card’s lifespan considerably.

That being said the graphic card is the most frequently upgrade item in a PC system and the most expansive, with that in mind when the newest hottest game does come out and you do want to play consider lowing the resolution and details a bit and see if you can live that performance. If not google your card and find out how other have overclocked it successfully and see if that sits well with you. But should all else that fail only then you should whip out the leather bag of money to fulfil your gaming needs.